[PATCH 30/32] selftests/nolibc: add test for snprintf() truncation

[Thomas Weißschuh]

Now that we have a proper snprintf() implementation,
make sure truncation is handled properly.

Signed-off-by: Thomas Weißschuh <thomas.weisssc...@linutronix.de>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c 
b/tools/testing/selftests/nolibc/nolibc-test.c
index 
a45fded42c14110c97c4c899d04dba8e676dfd49..0a891c40e2afbb398ae39b43dbe977efdab042e2
 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1290,7 +1290,8 @@ static int expect_vfprintf(int llen, int c, const char 
*expected, const char *fm
 
 
        va_start(args, fmt);
-       w = vsnprintf(buf, sizeof(buf), fmt, args);
+       /* Only allow writing 21 bytes, to test truncation */
+       w = vsnprintf(buf, 21, fmt, args);
        va_end(args);
 
        if (w != c) {
@@ -1396,6 +1397,7 @@ static int run_printf(int min, int max)
                CASE_TEST(pointer);      EXPECT_VFPRINTF(3, "0x1", "%p", (void 
*) 0x1); break;
                CASE_TEST(uintmax_t);    EXPECT_VFPRINTF(20, 
"18446744073709551615", "%ju", 0xffffffffffffffffULL); break;
                CASE_TEST(intmax_t);     EXPECT_VFPRINTF(20, 
"-9223372036854775807", "%jd", 0x8000000000000001LL); break;
+               CASE_TEST(truncation);   EXPECT_VFPRINTF(25, 
"01234567890123456789", "%s", "0123456789012345678901234"); break;
                CASE_TEST(scanf);        EXPECT_ZR(1, test_scanf()); break;
                case __LINE__:
                        return ret; /* must be last */

-- 
2.48.1